Solar cells use the photovoltaic effect for directly converting sunlight into electrical energy. This effect is not just restricted to sunlight, but can also be used for converting light—or more generally electromagnetic radiation—from other sources. In particular, mention may be made of optical power transmission (also known as “power over fiber”). In this technique, photovoltaic cells are irradiated with artificial light (or more generally: artificially generated electromagnetic radiation) which is generated by means of lasers, LEDs or halogen emitters, for example, in order to supply energy to small consumers, for example. It is thus possible to implement energy transmission (more precisely: power transmission) without metal cables and by this means to avoid short circuits, damage as a result of overvoltages and the like. The artificial electromagnetic radiation is transmitted to the photovoltaic cell either via the air or by means of dense media such as fiber optic cables, for example.